Robotic surface treating system

ABSTRACT

A vacuum cleaning system including a robotic unit including a traction arrangement, a docking interface and an articulated arm defining an end effector. The end effector includes a suction tool. The robotic unit defines a suction flow path which extends from the suction tool to the docking interface. The system further includes a handheld vacuum cleaner configured to be docked with the docking interface, the handheld vacuum cleaner including a vacuum motor for drawing air through the suction flow path when docked with the docking interface.

TECHNICAL FIELD

The invention relates to a robotic surface treating system, andparticularly though not exclusively to a robotic vacuum cleaning system.

BACKGROUND

The robotic vacuum cleaner market has grown hugely over the past decade.Changes in lifestyle, increased disposable income, urbanisation andgrowing focus on labour-saving devices are some of the factors that haveboosted market growth, and the trend seems to be set to continue.

Whilst the robotisation of vacuum cleaners has seen more products enterthe market, the form factor of such robots has not tended to diversify.Generally, robotic vacuum cleaners available on the market are discoidalin shape, with a low height so they can travel underneath furniture inorder to clean there. The main technological developments have focussedon improving navigational capabilities to improve autonomy, bin emptyingsystems and run time. In the main, however, the robotic vacuum cleanermarket includes many generally circular machines that offer very littlein terms of differentiation.

Some effort has been made to improve the functionality of robot vacuumcleaners to cope with demanding environments. For example, US2020/001468describes a robotic cylinder-style machine which has a cleaner head thatcan locomote separately. The cleaner head can therefore driver itselfaway from the main body of the machine to as to stretch underneathfurniture.

US2018/317725 and US2010/0256812 describe discoidal robots which areequipped with robotic arms. However, neither of these examples appearsto be a practical application, and the utility of the robotic arm ineach case seems to be limited.

It is against this background that the embodiments of the invention havebeen devised.

SUMMARY OF THE INVENTION

According to an aspect of the invention, there is provided a surfacetreating system comprising a robotic unit comprising a main body, atraction arrangement, and an articulated arm, wherein the articulatedarm comprises includes an upper arm section and a lower arm section,wherein the upper arm section is attached to the main body at a shoulderjoint, and wherein the lower arm section is attached to the upper armsection at an elbow joint, and wherein an end effector is defined at adistal end of the lower arm section. The shoulder joint and the elbowjoint are configured such that the upper arm section and the lower armsection are pivotable in a generally vertical plane relative to a groundplane defined by the traction arrangement, and wherein the articulatedarm is movable to a stowed position, in which position no part of thearticulated arm extends above an uppermost extremity of the roboticunit.

The surface treating system may be particularly suited to being arobotic vacuum cleaner. Beneficially, the invention provides aparticularly compact arrangement of machine with the advantage of arobotic arm which improves the flexibility of the machine to clean inawkward places. Since the articulated arm does not extend above theupper extremity or the ‘top’ of the robot during its movement, thismeans that the robotic system does not have to take account for thevertical position of the arm when it is manoeuvring around the floor andunder objects. The processing requirements are therefore simplified.

In addition to being lower that the top of the robotic unit in thestowed position, the articulated arm may further be configured so thatthe arm is always lower that the top of the robot, even during movementof the arm between stowed and deployed positions.

The articulated arm may further include a wrist joint which is rotatableabout an axis defined by a forearm member of the articulated arm. Thewrist joint may therefore be rotatable about an axis which is transverseto the axes of the shoulder and elbow joints. One advantage of this isthat the elbow section of the arm has a dual function; to rotate andextend, so as to provide further dexterity for the articulated arm.

The articulated arm may comprise a tool mount for selectively mounting atool thereto, and this enables a variety of cleaning tools to beattached to the cleaning system. The articulated arm may furthercomprise a suction nozzle, in the case of a vacuum cleaner, such thatthe robotic unit defines an airflow path in communication with thesuction nozzle.

The articulated arm may be foldable into a stowed state in which anupper arm portion of the articulated arm extends in a direction that issubstantially perpendicular to the ground plane. This provides aparticularly compact arrangement as the arm can be folded back againstthe main body of the cleaning system to take up less floor space.

Beneficially, the robotic unit may comprise a docking interface forreceiving a handheld vacuum cleaner in releasable engagement. So,although in some examples the robotic unit may incorporate an integratedsuction motor and associated equipment, the illustrated example of aseparate robotic unit and dockable handheld vacuum cleaner provide aparticularly flexible arrangement which, in effect, provides the userwith a ‘2-in-1’ machine.

Notably, the handheld vacuum cleaner may define a longitudinal axisalong which a suction nozzle and a vacuum motor are oriented, whereinthe handheld vacuum cleaner is mounted to the docking interface so thatthe longitudinal axis extends transversely, and optionallyperpendicularly, to the ground plane defined by the tractionarrangement. The handheld vacuum cleaner may also comprise a pistol gripand wherein, when the handheld vacuum cleaner is mounted to the dockinginterface, the pistol grip extends over at least a part of the main bodyof the robotic unit. This provides improved machine weight distributionin some examples of the invention. This may particularly be the casewhen the pistol grip supports a battery pack on the end thereof.

The main body of the robotic unit may be generally cylindrical in shape.Advantageously, the invention provides a particularly user friendlycleaning system for a user who is able to use the handheld vacuumcleaner for spot cleaning or larger cleaning tasks, but is then able todock the handheld vacuum cleaner onto the robotic unit for autonomouscleaning tasks. The handheld vacuum cleaner is mounted on the roboticunit in a configuration that provides an ergonomic mounting position fora user to grasp the handheld vacuum cleaner to engage and disengage itfrom the robotic unit.

Conveniently, the robotic unit and the handheld vacuum cleaner may shareone or more common suction tools, which means that both machines can beoptimised for the surfaces they are intended to clean. The suction toolsmay be passive, that is without a motorised bush bar or agitator, suchas may be the case for floor tools optimised for hard floors, or thesuction tools may be motorised which makes them particularly suited topiled floor coverings such as carpets and rugs.

Within the scope of this application it is expressly intended that thevarious aspects, embodiments, examples and alternatives set out in thepreceding paragraphs, in the claims and/or in the following descriptionand drawings, and in particular the individual features thereof, may betaken independently or in any combination. That is, all embodimentsand/or features of any embodiment can be combined in any way and/orcombination, unless such features are incompatible. The applicantreserves the right to change any originally filed claim or file any newclaim accordingly, including the right to amend any originally filedclaim to depend from and/or incorporate any feature of any other claimalthough not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects of the invention will now be described, byway of example only, with reference to the accompanying drawings, inwhich:

FIG. 1 is a is a side view of a vacuum cleaning system, in accordancewith an example of the invention, comprising a robotic drive modulehaving a robotic arm, and a handheld vacuum cleaner mounted on therobotic drive module;

FIG. 2 is a perspective view of the vacuum cleaning system of FIG. 1 ,with the robotic arm in a fully deployed state;

FIG. 3 is a side view of the vacuum cleaning system, with the arm in adeployed state like that in FIG. 2 ;

FIG. 4 shows the handheld vacuum cleaner in a stick vac configuration;

FIG. 5 is a schematic view of the handheld vacuum cleaner on its own,depicting some of its significant internal components;

FIGS. 6 a and 6 b are perspective views of the vacuum cleaning systemwhen viewed from the rear, where FIG. 6 a shows the handheld vacuumcleaner docked on the robotic drive module, and FIG. 6 b shows thehandheld vacuum cleaner separated from the robotic drive module;

FIG. 7 is a perspective view of the robotic drive module from the rearwith a dock insert separated from the docking portion, and FIG. 8 a-cshow various view of the dock insert; and

FIG. 9 a shows a perspective view of the vacuum cleaning system from thefront, and FIG. 9 b shows a comparable view but which emphasises anairflow path through the machine.

Note that features that are the same or similar in different drawingsare denoted by like reference signs.

SPECIFIC DESCRIPTION

A specific embodiment of the invention will now be described in whichnumerous features will be discussed in detail in order to provide athorough understanding of the inventive concept as defined in theclaims. However, it will be apparent to the skilled person that theinvention may be put into effect without the specific details and thatin some instances, well known methods, techniques and structures havenot been described in detail in order not to obscure the inventionunnecessarily.

In overview, the invention provides a novel type of robotically-drivensurface treating system, which is embodied in the illustrated examplesas a vacuum cleaning system. The cleaning system is a hybrid designwhich comprises a robotic drive unit or module, and a handheld vacuumcleaner that is removably attachable to the robotic drive module.Moreover, the robotic drive module is equipped with a robotic arm whichcarries a cleaning tool or head on its distal end. The robotic armtherefore provides the robotic cleaning system with an extended reach sothat it can clean under low-lying furniture. A convenient feature of thesystem is that the cleaning tool which is attachable to the distal endof the robotic arm, can also be attached to the handheld vacuum cleaner,either directly or via a wand extension tube. The cleaning system istherefore particularly convenient because a user can use the handheldvacuum cleaner to carry out spot-cleaning or more wide-spread cleaningtasks, e.g. when it is in stick-vac mode, but then the cleaner head canbe installed onto the robotic drive module so that it can carry outautonomous cleaning tasks on a schedule that suits the user. Furtherfeatures and advantages will become apparent from the discussion thatfollows.

The illustrated figures show a robotic vacuum cleaner 2 in accordancewith an example of the invention. Referring firstly to FIGS. 1 to 3 ,the robotic vacuum cleaner 2 comprises two main parts. The first part isa robotic drive section, unit, or module and is labelled generally as‘4’ and the second part is a handheld vacuum cleaner, which is labelledgenerally as ‘6’. As will be appreciated, the handheld vacuum cleaner 6is separable from the robotic drive module 4 such that the handheldvacuum cleaner 6 can be used on its own as a vacuum cleaning machinewhen it is undocked from the robotic drive module 4, or it may functiontogether with the robotic drive module 4 to provide an autonomous vacuumcleaner system 6. As can be seen, FIGS. 1 to 3 show the robotic drivemodule 4 and the handheld vacuum cleaner 6 in a docked state, whilstFIG. 6 b shows the robotic drive module 4 and in a separated or undockedstate.

In this example, the machine is a vacuum cleaner, but it is alsoenvisaged that various adaptations may be made so that it performs othersurface treating functions such as mopping, polishing,sanitiser-spraying and so on. So, the cleaning system in accordance withthe invention should also be considered to extend to surface treatingappliances or systems. For present purposes, however, the discussionwill refer to a vacuum cleaner, but it should be appreciated that theembodiments of the invention may have broader application to generalsurface treating functionality.

Returning to FIGS. 1 to 3 , it will be appreciated that the roboticdrive module 4 and handheld vacuum cleaner 6 are dockable so as tofunction as a self-propelled robotic vacuum cleaner. In this respect,the robotic drive module 4 provides the locomotion requirements of themachine, whilst the handheld vacuum cleaner 6 provides the suctionpower.

It is envisaged that each sub-unit may provide its own power, such thatthe robotic drive module 4 will include an on-board battery pack (notshown) to provide power to its respective drive motors (not shown),whilst the handheld vacuum cleaner 6 includes a battery pack to providepower to its on-board vacuum motor. However, it is also envisaged thatpower transfer between the robotic drive module 4 and the handheldvacuum cleaner 6 would be beneficial, during charging for example.Usefully, therefore, the handheld vacuum cleaner 6 can be used on itsown, either in the form of a handheld vacuum cleaner or in the form of astick-vac machine if the user wants to perform their own cleaning, forexample to spot-remove debris from certain areas in the house. However,the handheld vacuum cleaner 6 can be docked onto the robotic drivemodule 4 such that the two machines then function as an autonomousvacuum cleaner.

At this point it should be appreciated that the robotic drive module 4would also be provided with a suitable navigation system which would beresponsible for mapping, path planning and task scheduling operations.However, this functionality is beyond the scope of this discussion andso further explanation of these aspects will be omitted.

With reference also to FIGS. 4 and 5 , it will be noted that thehandheld vacuum cleaner has a form factor of a machine currentlymarketed by the applicant as the Dyson V10 or V11. Although the overallform factor of the handheld vacuum cleaner 6 is therefore known in theart, a brief overview will now follow for an improved understanding.

The handheld vacuum cleaner 4 comprises a main body 10 having anelongate handle 12, a cyclonic separating unit 14 and a suction inlet16. As shown the suction inlet 16 is formed as a short nozzle but acleaning tool or wand extension piece could be releasably attached tothe suction inlet 16 as required. The cyclonic separating unit 14 has alongitudinal axis X and extends away from the handle 12 such that thesuction inlet 16 is at the end of the cyclonic separating unit 14 whichis furthest from the handle 12.

The main body 10 comprises a suction generator 20 including a motor 22and an impeller 24 which are located above and towards the rear of thehandle 12. A battery 26 is located beneath the handle 12. As shown, thebattery 26 is located at the end of the handle 12. The handle 12 takesthe form of a pistol grip, and a trigger 28 is provided an upper end ofthe handle 12 for convenient operation. Optionally, and as seen here, atrigger guard 29 extends forwardly from the handle and around the frontof the trigger 28. As can be seen, for ergonomic reasons, the handle 12is generally transverse to the longitudinal axis X of the main body andextends along a handle axis H so as to form an angle 01 therewith, whichis this example is approximately 110 degrees.

The cyclonic separating unit 14 comprises a primary cyclonic separator30 and a plurality of secondary cyclonic separators 32, which arepositioned downstream from the primary cyclonic separator 30 and arearranged in a circular array about the axis X. Such a configuration isconventional in cyclonic vacuum cleaning technology. The primarycyclonic separator 30 comprises a separator body 34 in the form of a binhaving a cylindrical outer wall 36 and an end wall 38, which define atleast in part a cyclonic separator chamber 40.

The separator chamber 40 is annular in form and extends about thelongitudinal axis X. The axis of the separator chamber 40 therefore iscoincident with the longitudinal axis X of the machine.

In terms of the flow path through the machine, the suction inlet 16merges into a central duct 42 that runs centrally through the separatorchamber 40, from the end wall 38, along the longitudinal axis X of themachine.

The central duct 42 terminates at a primary cyclone inlet 44 whichdischarges into the separator chamber 40 near to the top end of theprimary cyclonic separator 30. Although not shown clearly in FIG. 5 ,the primary cyclone inlet 44 is angled at a tangent to the motion of airin the separator chamber 40 in use, as is conventional.

The bottom end of the separator chamber 40 near to the end wall 38 andadjacent part of the cylindrical outer wall 36 together define a dirtcollector or bin 46, which serves to collect the relatively largeparticles that are spun out of the circumferential airflow in theseparator chamber 40. The end wall 38 is pivotable with respect to thecylindrical outer wall 36 so that it can be opened to dischargecollected dirt from the bin 46. It should be noted at this point thatthe details of the bin opening mechanism and other related details maybe conventional and so further discussion on these points will beomitted. This discussion will therefore focus on the main aspects of thehandheld vacuum cleaner 6.

As has been mentioned, the cyclonic separating unit 14 includes a set ofsecondary cyclonic separators or ‘cyclones’ 32 which have a geometryoptimised for separating fine particles from the flow of air through themachine compared to the relative large particles for which the primarycyclonic separator 30 is optimised. Airflow transitions from theseparator chamber 40 of the primary cyclonic separator 30 to thesecondary cyclones 32 through a cylindrical permeable shroud 48 thatextends about the exterior of the central duct 42. The shroud 48therefore extends about the longitudinal axis X and is coaxialtherewith. The shroud 48 is permeable to air, in the form of aperforated panel such as a mesh, for example, and therefore forms an airoutlet from the separator chamber 40 which serves to catch fibrousmaterial on the shroud 48.

The shroud 48 encircles a duct 50 which extends longitudinally along themachine and which defines inlets 51 to the plurality of relatively smallsecondary cyclones 32. In the usual way, the secondary cyclones 32 aregenerally conical in form and define a dirt outlet at their respectivetips 52 which discharge into a fine dust collector 54. In this example,the fine duct collector 54 is defined by the outer cylindrical wall ofthe cyclonic separating unit 14 in a radial outward position withrespect to the main dirt collector 46. In this configuration therefore,when the end wall 38 is opened, the main dirt collector 46 and the finedust collector 54 are opened so that direct can be emptied from themachine.

In overview, during use the handheld vacuum cleaner 6 is activated by auser pressing the trigger 28 which powers up the suction generator 20.The suction generator 20 therefore establishes a negative pressuredifferential through the machine which draws air flow through thesuction inlet 16, up the central duct 42 and into the separator chamber40 where it rotates around the longitudinal axis X. The rotational flowin the separator chamber 40 produces a cyclonic action that separatesrelatively heavy or large dirty particles from the air. Due to theorientation that the handheld vacuum cleaner 6 is typically used, theselarge dirt particles will tend to collect in the main dirt collector 46.The partially cleaned air then passed through the shroud 48, along theduct 50 and into the secondary cyclones 32 which act to separate smallerand lighter particles of air, which are expelled through the cyclonetips 52. Clean air is drawn out of respective outlets 60 of thesecondary cyclones 32 and through the suction generator 20, where it isdischarged to atmosphere.

Notably, FIG. 5 shows the handheld vacuum cleaner in a ‘bare’ state, inwhich it does not have a cleaning tool attached to it. However, itshould be appreciated that various cleaning attachments may be coupledto the handheld vacuum cleaner as required. In this respect, FIG. 4shows the handheld vacuum cleaner 6 with a wand 62 attached, which turnsthe handheld vacuum cleaner 6 into a stick vacuum cleaner or‘stick-vac’. Here, the distal end of the wand 62 in turn has a motorisedcleaner head 64 attached to it which is optimised for cleaning hardfloors or other floor coverings such as carpets and rugs.

Having described the overall configuration of the handheld vacuumcleaner 6, the discussion will focus on the configuration of the roboticdrive module 4. This can be seen combined with the handheld vacuumcleaner 6 in many of the drawings, but it can also be seen on its own inFIGS. 6 b and 7.

The robotic drive module 4 comprises a main body 70 that is flanked by apair of wheels 72, one on either side of the main body 70. The wheels 72are circular in this example and comprise a discoidal hub 74, theperimeter of which defines or carries a traction surface 76. Thetraction surface 76 may be made of a different material than the hub 74to improve traction on certain surfaces. For example, the tractionsurface 76 could be a band-like element made of a grippy rubberisedmaterial or similar to provide improve traction on hard floors. Althoughthe robotic drive module 4 is provided with circular wheels in thisexample, it is also envisaged that another type of rolling arrangementcould be provided, for example in the form of a tracked drive system.The wheels therefore should be considered to be one type of tractionarrangement for the robotic drive module 4.

The wheels 72 are positioned on either side of the main body 70 and haveequal diameters. As such, their outer perimeters circumscribe animaginary cylindrical shape which defines a rolling axis 73, and withinwhich the structure of the main body 70 is contained. More specifically,in the illustrated example, the main body 70 is barrel-like in shapewith an outer diameter which is slightly smaller than the outer diameterof the wheels 62. Expressed another way, the main body 70 is generallycylindrical in form and has a diameter approximately the same as thediameter of the wheels 72, in this example.

The main body 70 can be considered to have a forward-facing side 78 anda rearward-facing side 80. The forward-facing side 78 supports a near-or proximal-end of a robotic arm 82. The rearward-face side 80 defines adocking interface, region or portion 84, and this will be described inmore detail later. As can be seen, therefore, the general barrel-likeshape of the main body 60 is interrupted by suitable recesses 86 for therobotic arm 70 and the docking portion 84.

The robotic arm 82 is movable with respect to the main body 70 andincludes an end effector 90 on its distal end to which different typesof cleaning tools can be attached. As shown in the Figures, the end ofthe robotic arm 82 has a motorised cleaner head 92 attached to it,including a rotatable agitator. The robotic arm 82 therefore provides asuction flow path for the robotic vacuum cleaner 2 which extends fromthe end of the robotic arm 82, along the robotic arm 82 to the main body70 of the robotic drive module 4 and to the handheld vacuum cleaner 6.FIGS. 9 a and 9 b illustrate this neatly as side-by-side views with someof the components of the machine removed so that a suction path 94through the machine can be appreciated.

In the illustrated embodiment, the robotic arm 82 is articulated and canmove between two main configuration: a stowed configuration in which thearm is folded up against the robotic drive module 4, and a deployedconfiguration in which in an extreme position the robotic arm extendsgenerally straight away from the robotic drive module 4 parallel to thefloor surface 101. The fully deployed configuration is shown clearly inFIGS. 2 and 3 , and in FIG. 3 it will be noted that a major part of therobotic arm 82 extends parallel to the floor surface 101. In this waytherefore, the robotic arm 82 takes up minimal space when in the stowedconfiguration since it is folded compactly against the robotic drivemodule 4, but it conveniently can extend in front of the robotic drivemodule 4 by a significant distance so it can stretch under pieces offurniture and into narrow gaps.

As shown, the robotic arm 82 comprises an upper arm portion 100 and alower arm or ‘forearm’ portion 102. The upper arm portion 100 has afirst end 104 that is coupled to the main body 70 and a second end 106that is coupled to the forearm portion 102. Similarly, the forearmportion 102 includes a first end 108 that is coupled to the upper armportion 100 and a second end 110 that defines the end effector 90.

Although the robotic arm 82 may be configured in various ways, it willbe noted that in the illustrated embodiment, the upper arm portion 100has a two-part structure such that it comprises parallel arm members 100a, 100 b. This provides the robotic arm 82 with a study construction anda suitable torsional rigidity that is more resistant to flexing andtwisting.

The connection between the upper arm portion 100 and the main body 70 isachieved by a pair of sockets 112 defined in the main body 60 whichreceive respective proximal ends of the pair of upper arm members 100 a,100 b to define a shoulder joint 114. Although not shown in FIGS. 1-3the main body 70 may include a suitable drive system to pivot the upperarm portion 100 with respect to the main body 70 at the shoulder joint114. Similarly, the distal ends of the upper arm members 100 a, 100 bdefine a yoked elbow joint 116 into which is received an end of theforearm portion 102. The elbow joint 116 is suitably configured to allowthe forearm portion 102 to pivot relative to the upper arm portion 100.Separate drive motors (not shown) may be used for this purpose, or thejoint 116 may be driven by a drive mechanism powered by the main body60.

Notably, the shoulder joint 114 and the elbow joint 116 definerespective pivot axes, 114′,116′. As shown, the pivot axes 114′,116′ arearranged parallel to the ground plane. As such, the pivot axes 114′,116′are also parallel to the rolling axis 73, and perpendicular to thelongitudinal axis X of the handheld vacuum cleaner 6. By virtue of theparallel horizontal arrangement of the pivot axes 114′,116′ thearticulated arm 82 is arranged to pivot about both the shoulder joint114 and the elbow joint 116 through a substantially vertical plane P.

The upper arm portion 100 has a dog-leg shape when viewed from the side,in this illustrated example, and so each of the upper arm members 100 a,100 b comprises a first section 120 that defines a shallow angle withrespect to a second section 122. This is best seen in FIG. 3 , whichshows clearly that a significant part of the upper arm portion 100, thatis, the entirety of the second section 122 thereof, is positionedadjacent a floor surface 101 when the robotic arm 82 is in the fullydeployed position. This is beneficial because it enables a significantpart of the robotic arm 82 to lay flat against an adjacent floor surface101. The first section 120 of the upper arm members 100 a, 100 binclines downwardly from the shoulder joint 114 of the main body 70 andthen straightens to extend parallel to the floor.

As has been mentioned, the robotic arm 82 can be folded back from itsextended or deployed position, shown in FIGS. 2 and 3 , to a stowedstate as shown in FIG. 1 . It can also be controlled to adopt positionedintermediate the two extreme positions. The two-part parallel structureof the upper arm portion 100 is beneficial in this context because itpermits the lower arm section 102 to pivot around the elbow joint 116and nest or sit between the parallel arm members 100 a, 100 b of theupper arm portion 100. This allows a particularly compact stowagearrangement for the robotic arm 82. As can be seen in FIG. 1 , forexample, in the stowed position the lower arm portion 102 is orientedvertically and is flanked by at least a part of the parallel upper armmembers 100 a, 100 b, that is to say by the second sections 122 thereof.What is more, the upper extremity of the robotic arm 82 is not thehighest point of the robotic vacuum cleaner 2, since despite itsvertical orientation, it is lower than the vertical height reached bythe upper extremity of the handheld vacuum cleaner 6, which is indicatedby the line V. This can be seen clearly in FIG. 1 . Expressed in anotherway, no part of the robotic arm 82 extends above the upper extremity ofthe robotic vacuum cleaner 2. This is the case either when the arm 82 isin the stowed position or when it deploys.

The two-part structure of the upper arm portion 100 also providesflexibility in terms of how the airflow path is routed from the cleanerhead to the main body 70. For example, one of the upper arm members 100a, 100 b can be configured to define the airflow path, whilst the otherof the upper arm members 100 a, 100 b can be configured to carry therequired mechanical and electrical components to power the elbow joint116. FIGS. 9 a and 9 b illustrate this clearly in which a first pipesection 130 extends inside the forearm portion 102 vertically upwardsfrom the cleaner head 92 and which bends through a 180 degree angle toform a second pipe section 132 which extends downwardly through one ofthe arm sections 100 a of the upper arm portion 100 and into the mainbody 70 of the robotic drive module 4.

Having described the robotic arm aspects of the vacuum cleaning system2, the discussion will now turn to general configuration aspects anddocking aspects of the vacuum cleaning system 2.

As has been mentioned above, the main body 70 defines the dockingportion 84 which is adapted to accept the handheld vacuum cleaner 6 insuch a way as to complete the airflow path through the machine andtherefore to provide a source of suction. The handheld vacuum cleaner 6is arranged in an upright orientation with respect to the floor surface(see FIG. 3 ) when it is docked with the robotic drive module 4. In thisway, the longitudinal axis X of the handheld vacuum clearer 6 issubstantially vertical in the illustrated example. Expressed anotherway, the longitudinal axis X of the handheld vacuum cleaner 6 isgenerally perpendicular to the floor surface 101, which defines a groundplane. This arrangement provides an ergonomic angle for a user to dockthe handheld vacuum cleaner 6 to the robotic drive module 4. This isbecause a user would tend to hold the handheld vacuum cleaner 2 in sucha way to approach the docking portion 84 from above so a verticaldocking arrangement is convenient for the user.

As well as being oriented generally vertically, the handheld vacuumcleaner 6 is arranged in the docking portion 84 so that its handle 12points in the forward direction. That is to say, the linear section ofthe handle 12 is aligned with a fore-aft axis F of the main body 60. Ascan be seen in FIGS. 1-3 , the arrangement of the handheld vacuumcleaner 6 in the docking interface 84 and its orientation is such thatthe handle 12 extends over the top of the main body 70 of the roboticdrive module 4. With respect to the floor surface/ground plane 101, thehandle 12 is generally horizontal, although it should be appreciatedthat in the illustrated embodiment the handle 12 is not preciselyhorizontal but defines a small angle therewith.

As will be apparent particularly from the side views of the vacuumcleaning system 2, the handle 12 extends over the robotic drive module4, in the fore-aft direction F, to an extent that it passes over andextends beyond the rolling axis 73 that is defined by the wheels 72.Notably, the battery 26 is located at the end of the handle 12 and, inthe arrangement shown, when the handheld vacuum cleaner 6 is docked onthe robotic drive module 4, the battery 26 can be considered to be in acantilevered arrangement. As such, the battery 26 is supported on theend of the handle 12, which extends in a horizontal direction when thehandheld vacuum cleaner 6 is docked on the robotic drive module 4.

Notably, the handle 12 and battery 26 have a combined length so that theend of the battery 26 is at a horizontal position which is approximatelyin line with the end of the wheels 72. So, the battery 26 can beconsidered to extend over the top of at least a part of the roboticdrive module 4. Furthermore, it should be noted that the direction inwhich the handle 12 extends is aligned with the direction of the roboticarm 82, so as to be in parallel therewith. The handle 12 can thereforebe considered to point in the forward direction of the vacuum cleaningsystem 2. One benefit of this arrangement is that the weight of thebattery 26 provides a balancing effect, as the battery 26 is positionedon the other side of the rolling axis 73 to the main body 10 of thehandheld vacuum cleaner 6. Together with the mass of the articulated arm82, this arrangement provides a convenient means to provide balance tothe twin-wheeled arrangement of the robotic drive module 4.

It is particularly apparent from FIG. 1 , for example, that the roboticarm 82 in the stowed position is in a folded upright configuration inwhich a surface of the robotic arm 80 abuts the distal surface of thebattery 26. In effect, therefore, the battery 26 provides a movementbackstop for the motion of the robotic arm 82 as it travels into itsstowed position.

A further benefit associated with the vacuum cleaning system 2 is due tothe exchangeability of the cleaner head 92 between the robotic arm 82and the handheld vacuum cleaner 4. This provides consistency of cleaningwhen either machine is used to clean the floor and also provides a moreefficient package. To permit the sharing of cleaning head, both thesuction inlet 16 of the handheld vacuum cleaner 6 and the end effector90 of the robotic arm 82 are provided with a connector or tool mount ofthe same format. Therefore, the same cleaner head 92 can be releasablyclicked into place on either machine. As well as motorised cleanerheads, it will be appreciated that the handheld vacuum cleaner 6 may beequipped with other cleaning tools, such as crevice tools or mattresstools as desired by the user. Such cleaning tools may be motorised ornon-motorised.

Turning now to FIGS. 6 a, 6 b , 7 and FIGS. 8 a-c , the discussion willnow focus on the docking aspects of the vacuum cleaning system. WhereasFIG. 6 a shows the vacuum cleaning system 2 with the handheld vacuumcleaner 6 docked onto the robotic drive module 4, FIGS. 6 a and 7 showthe robotic drive module 4 on its own. Notably, however, FIG. 6 bdepicts a dock insert 138 engaged with the robotic drive module 4whereas FIG. 7 shows the dock insert 138 removed from the robotic drivemodule 4.

The docking portion 84 is defined generally by a floor 140 and a curvedwall 142 in the rear side 80 of the main body 70 of the robotic drivemodule 4. The curved wall 142 is shaped to match approximately thecircular geometry of the bin of the handheld vacuum cleaner 6. As aresult, the handheld vacuum cleaner 6 appears to partially ‘sit’ in therobotic drive module 4 in a piggy-back configuration. The floor 140 ofthe docking portion 84 includes the electrical connection and airflowconnection which allows the handheld vacuum cleaner 6 to interfaceeffectively with the robotic drive module 4.

As can be seen in FIG. 6 b , an airflow connector 144 is defined at thecentre of the floor 140 of the docking region 84 and this airflowconnector 144 is configured to mate with the suction inlet 16 of thehandheld vacuum cleaner 6. Likewise, situated next to the airflowconnector 144 is an electrical connector 146 which is configured to bemated with a respective electrical connector 148 of the handheld vacuumcleaner 6.

Whereas the airflow connector 144 completes the airflow path through themachine, from the cleaner head 92, along the robotic arm 82 into themain body 70, through the docking portion 84 and finally to the handheldvacuum cleaner 6, the electrical connector 146 may provide power and/ordata transfer between the robotic drive module 4 and the handheld vacuumcleaner 6. For example, in terms of electrical power, it is an optionfor the main body 70 to accommodate a larger battery system than thehandheld vacuum cleaner 6 so it may be advantageous to enable therobotic drive unit 4 to power the handheld vacuum cleaner 6. Similarly,when the vacuum cleaning system 2 is docked to an appropriateground-based docking station for the purposes of charging, the handheldvacuum cleaner 6 may be charged through the robotic drive module 4.

The electrical connection between the robotic drive module 4 and thehandheld vacuum cleaner 6 may also be used for data transfer. Forexample, the user may interact with a user interface 150 provided on thehandheld vacuum cleaner 6 in order to command operational functions forthe vacuum cleaning system 2. Therefore, the electrical connector 146provides a means for the commands to be transmitted from the handheldvacuum cleaner 6 to the robotic drive module 4 whereupon they can beacted on by the onboard control system (not shown).

In some examples of the invention, it is envisaged that the dockingportion 84 may be an integral part of the main body 70 having a fixedconfiguration so only a single type of handheld vacuum cleaner 6 is ableto dock with it. However, in other examples, it is envisaged that thedocking portion 84 may be reconfigurable to enable more than one type ofhandheld vacuum cleaner to dock with it. One way in which this could beachieved is with movable features on the docking portion 84 which wouldenable a user to configure the docking portion 84 selectably tointerface to a particular handheld vacuum cleaner type. For example, therear wall 142 may feature sliding sections which could be switchedbetween different positions in order to change the geometry of thedocking portion 84 thereby providing support to different types ofhandheld vacuum cleaners.

Another option is shown in the illustrated examples. Here the dockingportion 84 is defined at least in part by the removable dock insert 138.The dock insert 138 is able to be swapped with a different dock inserthaving a geometry that has been designed to match a different type ofhandheld vacuum cleaner.

The dock insert 138 comprises base section 152 and a rear wall 154 whichare shaped so as to complement a correspondingly shaped recess 156defined in the main body 70 of the robotic drive module 4.

The base section 152 is generally circular in shape and defines agenerally flat annular platform 158 for receiving the leading end of thebin of the handheld vacuum cleaner 6. The annular platform 158 surroundsthe airflow connector 144 and electrical connector 146.

The rear wall 154 extends upwardly from the base section 152 andterminates in a transversely extending cap section 160. The rear wall154 extends about approximately 25% of the perimeter of the base section152 so as to fit into the recess 156 in the main body 70. In order toconform to the cylindrical outer surface of the bin of the handheldvacuum cleaner, the rear wall 154 is curved in the horizontal plane witha radius of curvature that is comparable to the radius of the basesection 152. The rear wall 154 therefore continues the curvature of therear wall 142 in the main body 70, portions of which flank the rear wall154 of the dock insert 138.

The cap section 160 has a curved upper surface 162 which extends awayfrom the rear wall 154 in a direction opposite the base section 152. Ascan be seen by observing FIG. 7 , the curved upper surface 162 of thecap section 160 matches the curved upper surface of the generallycylindrical main body 70. Therefore, when the dock insert 138 is fittedto the main body 70, the curved upper surface 162 of the dock insert 138lays flush with, and therefore blends into, the curved upper surface ofthe main body 70.

Observing FIG. 8 c , which shows clearly the underside of the dockinsert 138, it will be seen that that a rear edge of the base section152 is provided with an electrical port 164 and an airflow port 166which correspond to the electrical connector 146 and the airflowconnector 144 respectively. Likewise, FIG. 7 shows the docking portion84 without the dock insert 138 and it will be appreciated that thedocking portion 84 is provided with a respective electrical port 170 andairflow port 172 which are able to mate with the respective ports 164,166 in the dock insert 138.

Various modifications to the illustrated examples are possible withoutdeparting from the scope of the invention as defined by the claims.

1. A surface treating system comprising: a robotic unit comprising amain body, a traction arrangement, and an articulated arm, wherein thearticulated arm comprises includes an upper arm section and a lower armsection, wherein the upper arm section is attached to the main body at ashoulder joint, and wherein the lower arm section is attached to theupper arm section at an elbow joint, and wherein an end effector isdefined at a distal end of the lower arm section, wherein the shoulderjoint and the elbow joint are configured such that the upper arm sectionand the lower arm section are pivotable in a generally vertical planerelative to a ground plane defined by the traction arrangement, whereinthe articulated arm is movable to a stowed position, in which positionno part of the articulated arm extends above an uppermost extremity ofthe robotic unit, and wherein the main body of the robotic unit includesa docking interface for receiving a handheld vacuum cleaner inreleasable engagement.
 2. The vacuum cleaning system of claim 1, whereinthe traction arrangement comprises a pair of rolling elements each ofwhich defines a matching circumferential shape, wherein the pair ofrolling elements are spaced apart along a rolling axis such that thecircumferential shapes of the rolling elements define an imaginarycylindrical volume between them with a cross sectional area that matchesthe circumferential shape, wherein the main body is configured so as notto extend outside of the imaginary cylindrical volume.
 3. The system ofclaim 1, wherein the main body is generally cylindrical in shape.
 4. Thesystem of claim 1, wherein the handheld vacuum cleaner has alongitudinal axis along which a suction nozzle and a vacuum motor areoriented, wherein the handheld vacuum cleaner is mounted to the dockinginterface so that the longitudinal axis extends transversely, andoptionally perpendicularly, to the ground plane defined by the tractionarrangement.
 5. The system of claim 1, wherein the handheld vacuumcleaner comprises a pistol grip and wherein, when the handheld vacuumcleaner is mounted to the docking interface, the pistol grip extendsover at least a part of the main body of the robotic unit.
 6. The systemof claim 5, wherein the pistol grip supports a battery pack on the endthereof.
 7. The system of claim 1, wherein the docking interface isdefined on a first side of the traction arrangement.
 8. The system ofclaim 7, wherein the articulated arm extends from the main body on asecond side of the traction arrangement.
 9. The system of claim 1,wherein the upper extremity of the robotic unit is defined by thehandheld vacuum cleaner.
 10. The system of claim 1, wherein thearticulated arm is movable from the stowed position to a deployedposition, during which movement no part of the articulated arm extendsabove the uppermost extremity of the robotic unit.